Merge pull request #53 from jamezilla/master

Bug fix for running spring tests under rails >= 4.0 without spring testunit

lib/guard/test/runner.rb

@@ -82,10 +82,19 @@ def executables
         parts << case true
                  when drb? then 'testdrb'
                  when zeus? then 'zeus test'
-                 when spring? then 'spring testunit'
+                 when spring? then spring_command
                  else 'ruby'; end
       end
 
+      def spring_command
+        if Gem.loaded_specs["rails"] && Gem.loaded_specs["rails"].version < Gem::Version.create('4.0')
+          'spring testunit'
+        else
+          # rails > 4.0 supports passing a path to rake test
+          'spring rake test'
+        end
+      end
+
       def includes_and_requires(paths)
         parts = []
         parts << Array(options[:include]).map { |path| "-I\"#{path}\"" } unless zeus? || spring?